Hydroforming is a relatively new forming process wherein a tube is pressurized hydraulically and internally to deform the tube into a desired shape defined by a hydroforming die. The tube is first pre-bent and pre-formed and then mounted within the hydroforming die. While within the closed die the tube is pressurized hydraulically and is caused to deform plastically into a final finished profile.
Hydroforming offers several advantages over traditional stamp-and-weld fabrication processes, including improved structural strength and stiffness, as well as reduced tooling cost and improved dimensional accuracy. As noted above, a typical hydroforming process includes tube bending, pre-forming, pressurization, and post processing. In order to design and manufacture a hydroformed product cost effectively, numerical simulations are preformed in both the design stage and again in the manufacturing stage of the hydroformed part. Simulations are employed to satisfy three separate requirements. First, simulations are employed to assess design feasibility, with a focus being upon the selection of a proper tube for the finished workpiece. Second, simulation is used in the evaluation of a vehicle's functional attributes such as impact analysis and durability. This second type of simulation focuses upon workpiece or component thickness and deformation history for the hydroformed product, with initial results being used in subsequent vehicle performance analyses. Finally, hydroforming simulations are used for manufacturing purposes, such as tooling and process design.
Known hydroforming-modeling practices follow the sequential physical process and take a very long time, on the order of weeks, of demanding, tedious computer-aided engineering work. One important part of this work includes the set-up and modeling of the pre-form process during which a tube is deformed at different local positions in order to fit it into the hydroforming die. This step of the process traditionally takes a large amount of time.
The present invention greatly reduces the amount of time needed to simulate a hydroforming process, while improving the accuracy of the modeled process and the production capability to manufacture the modeled hydroformed component.